NOTES ON THE HABITS OF CERTAIN CRAWFISH. 83 
Dr. Hagen refers to the quotation from Dr. Godman, speaking 
of the crawfish, of which the latter writes, as Cambarus Diogenenes 
Girard, and considers it to be the same as C. Bartonii Fabricius ; 
although it seems to bear some resemblance to C. obesus Hagen, 
a southern and western species. One fact is certain, at least, 
that the specimens observed by Godman were in a stream near 
Philadelphia, a locality familiar to Girard. We have found no 
specimen about Trenton, New Jersey, that could be identified with 
C. obesus Hagen, although we have made very careful search, 
hoping to find more than the three species we have mentioned. 
Crawfish are strictly omnivorous animals but, although excellent 
Scavengers, do not feed wholly upon decayed animal and vegetable 
matters. We have frequently noticed that C. Bartonii in an 
aquarium breaks off the short stems of the common river-weed, 
and eats the main stem, after stripping it of its minute leaves. 
So too O. affinis, from beneath its sheltering flat stone, and C. 
Bartonii, in its safe burrow, will seize the minute young Cypri- 
noids, that pass up and down near the stream in such myriads, 
ever and anon peeping into the various little indentations in the 
banks. Such little fish when once fairly caught by the big, but 
by no means clumsy, *‘ hands” of a Cambarus, have no chance o 
escape, and are soon torn in pieces and devoured. 
Etheostomoids, or ‘ darters,” that habitually rest upon the 
bottoms of the streams they frequent, will usually take shelter 
underneathia stone, if one be near, when they are disturbed either 
by larger fishes, or by man. When a crawfish happens to have 
en up his abode under such a stone, it is seldom that the 
frightened “darter” escapes. Often have we seen the common 
_ Boleosoma Olmstedi take refuge as we have described and found, 
on examination, a Cambarus quietly resting underneath ‘the stone, 
with the luckless “ darter” in his claws. : 
Having had our attention particularly called to these crustaceans, 
during the past month of September only, we have, of course, 
_ Doted nothing of their breeding habits; but the very great num- 
pers of very small specimens half an inch to an inch and one 
half in length that we have found, seem to indicate that the 
animal is of slow growth during the firs summer of its exis- 
tence ; and on the other hand, we have failed to find any specimens 
= C. acutus more than four inches in length, the maximum size 
ng six and three-tenths inches, as given by Dr. Hagen. 
